A seacock is a type of valve used to control the intake or discharge of water through the hull of a marine craft. A seacock is typically operated by manually moving a handle between two positions to move a valve 90.degree. to open or close a conduit which extends through the hull. In many marine vessels, a propulsion engine for the vessel is cooled by water drawn in through the seacock in its open position by a self-priming pump which delivers the water to the internal cooling system of the engine. The water is drawn in from the body of water in which the vessel floats and is pumped back overboard through the engine's exhaust system. Typically, the seacock or seacocks controlling the flow of water to one or more engines in the vessel performed only the function of either permitting or preventing flow of water to the engine cooling system.
It is also customary to provide a vessel with one or more bilge pumps which, depending upon the size and sophistication of the vessel, are operated manually, electrically or mechanically from the engine for the purpose of periodically pumping out water which occasionally accumulates in the bilge. Bilge pumps are generally intended to pump out water which is present because of the gradual accumulation of water from ordinary minor leakage through or around various hull fittings throughout the craft or resulting from rough sea conditions. Such pumps are not generally capable of coping with a large inflow of water from an unexpected source such as an opening created by hull damage sustained from striking a submerge object or another craft.
In the event of such an emergency, the rapid and unexpected inflow of water could jeopardize the safety of the craft and those on board and could eventually sink the craft if immediate corrective action is not taken.
For this reason, various proposals have been made to use the engine cooling system as an additional pump so that, in the event of serious emergency conditions, the cooling system pump can extract water from the interior of the vessel rather than from the body of water surrounding the vessel, operating in conjunction with the bilge pumps to keep the vessel afloat until repairs or other steps appropriate to the circumstances can be taken.
However, structures for this purpose proposed in the past have had various disadvantages due to the arrangement of the system or for other reasons and have gained substantially no acceptance in the marine industry.